Chemically activated dental bleaching trays

ABSTRACT

Dental treatment trays and strips used to deliver a dental bleaching composition to a person&#39;s teeth are formed from a moisture resistant barrier material and include a bleaching agent destabilizer disposed on an inner treatment surface of the barrier layer that is positioned against the person&#39;s teeth during use. The bleaching agent destabilizer may be compounded with the moisture resistant material or otherwise disposed relative to the barrier layer so that at least some destabilizer is positioned on the inner treatment surface of the tray or strip so as to contact the dental bleaching composition during use.

RELATED APPLICATIONS

The present application claims the benefit of U.S. patent applicationSer. No. 11/849,075, filed Aug. 31, 2007 and entitled “DENTAL TREATMENTTRAYS AND STRIPS COMPRISING SILICONE” under 35 U.S.C §119, thedisclosure of which is incorporated by reference in its entirety. Apetition to convert the above application to provisional status wasfiled Oct. 26, 2007.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention is in the field of shaped, flexible dental traysand strips used to deliver a dental bleaching composition to a person'steeth. More particularly, the invention relates to flexible dental traysand strips with enhanced user comfort and tooth adhesion.

2. The Relevant Technology

Virtually all people desire white or whiter teeth. A common bleachingmethod involves the use of a dental tray that is custom-fitted to aperson's teeth and that is therefore relatively comfortable to wear. Onetype of customized tray is made by vacuum forming a sheet of moistureresistant thermoplastic polymer material over a stone cast of a person'steeth, after which the custom tray may be cut out. Another is customizeddirectly using a person's teeth as a template (e.g., “boil-and-bite”trays). Non-customized trays that approximate the shapes and sizes of avariety of users' dental arches have also been used. A dental bleachingcomposition is placed into the tray and the tray placed over theperson's teeth for a desired period of time.

Another tooth bleaching method involves placing a flexible bleachingstrip over a user's tooth surfaces. Conventional bleaching stripscomprise a flexible plastic strip coated with a dental bleaching gel ofmoderate viscosity and relatively low stickiness on the side of thestrip facing the user's teeth. To install the bleaching strip, a portionof the bleaching strip is placed over the front surfaces of the user'steeth, and the remainder is folded around the occlusal edges of theteeth and against a portion of the lingual surfaces.

Because of the generally poor adhesion of bleaching strips to the user'steeth, coupled with their generally flimsy nature, it is often difficultfor the user to maintain the bleaching strip in its proper position forthe recommended time. Conventional bleaching strips are prone to slipoff the teeth as a result of even minimal movement of the user's mouth,jaw or tongue. It is recommended that the user not eat, drink, smoke orsleep while wearing the bleaching strip. In some cases, the bleachingstrip can become so dislodged or mangled that it must be removed by theuser and replaced with a fresh bleaching strip to complete therecommended bleaching time.

Ultimately, the main impediment to successful bleaching is the failureof users to complete the prescribed bleaching regimen. If the bleachingapparatus is difficult to install over a person's teeth, requiresnumerous repetitions to achieve observable results, and/or isuncomfortable to wear, the user may simply give up and prematurely abortthe prescribed bleaching regimen. Thus, even if dental bleaching ispossible using a particular bleaching apparatus or method, it is lesslikely to occur if the inadequacies of the bleaching apparatus or methodcause a user to become discouraged before desired results are attained.

BRIEF SUMMARY OF THE PREFERRED EMBODIMENTS

The present invention generally relates to improved dental bleachingtrays and strips used to deliver a dental bleaching composition to aperson's teeth. The inventive dental bleaching trays and strips areformed from a moisture resistant (e.g., polymeric) material and includea bleaching agent destabilizer disposed on an inner treatment surface ofthe barrier layer that is oriented toward and adjacent to the person'steeth during use. The bleaching agent destabilizer may be compoundedwith a polymeric or other moisture resistant material from which thebarrier layer is formed so that at least some destabilizer is positionedon an inner treatment surface of the tray or strip during use.

Bleaching agent destabilizers may include any known bleaching agentdestabilizer that is capable of destabilizing a dental bleaching agentin order to accelerate bleaching. When peroxides are destabilized theymore rapidly release oxygen radicals, which are believed to beresponsible for the tooth bleaching effect. The bleaching agentdestabilizer is advantageously retained on the surface and/or within thepolymeric or other moisture resistant barrier layer of the tray or stripprior to use. Upon contact with a peroxide dental bleaching agent in thepresence of water, the destabilizer is able to activate or destabilizethe bleaching agent, resulting in the formation of free radicals fromthe peroxide for increased bleaching effect.

One class of bleaching agent destabilizers includes transition and/oralkaline earth metals or their ions. Non-limiting examples of suitablemetals and metal ions include magnesium, iron, titanium, cobalt, nickel,copper, platinum, tin, zinc, manganese, chromium, aluminum, silver, andcombinations thereof. Magnesium and/or iron ions are particularlypreferred. Another class of bleaching agent destabilizer includesenzymes, particularly organo-metallic enzyme containing transitionmetals, such as iron. Examples of organo-metallic enzymes include“peroxidase” and “catalase”.

One embodiment provides a tray or strip in which the bleachingcomposition is prefilled within the tray or pre-applied to the strip. Inone manner, this is made possible by providing the moisture-resistantbarrier layer including the bleaching agent destabilizer with aprotective rupturable membrane disposed between the barrier layer andthe dental bleaching composition so as to prevent premature contactbetween the dental bleaching agent and the bleaching agent destabilizeron or within the barrier layer. In another manner, this may be madepossible by providing an anhydrous dental bleaching composition. Theanhydrous dental bleaching composition may be disposed directly incontact with the barrier layer, and will not react prematurely becauseof the anhydrous nature of the bleaching composition. As soon as wateris added to the system (e.g., when contacted with saliva by placing thepre-filled tray or strip onto the teeth), reaction between thedestabilizer and bleaching composition will begin. Embodiments includingan anhydrous dental bleaching composition and no ruptureable membraneshould preferably be sealed within a protective package to preventabsorption of water from the surrounding air during shipment andstorage.

These and other advantages and features of the present invention willbecome more fully apparent from the following description and appendedclaims, or may be learned by the practice of the invention as set forthhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of thepresent invention, a more particular description of the invention willbe rendered by references to specific embodiments thereof, which areillustrated in the appended drawings. It is appreciated that thesedrawings depict only typical embodiments of the invention and aretherefore not to be considered limiting of its scope. The invention willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1 is a perspective view of an exemplary non-custom dental bleachingtray according to the invention;

FIG. 2A is an exploded view of a dental bleaching tray having anatomicalfeatures to improve fit and an optional complementary outer supporttray;

FIG. 2B is a perspective view showing the dental bleaching tray nestedwithin the outer support tray;

FIG. 3 is a perspective view of an exemplary dental bleaching stripaccording to the present invention;

FIG. 4 illustrates a pair of pre-filled tray assemblies similar to theassembly of FIG. 2B contained within a sealed protective package havinga peelable cover;

FIG. 5 is a cross-sectional view of a tray assembly including arupturable membrane between the barrier layer and the bleachingcomposition;

FIG. 6A illustrates a person placing a dental bleaching tray accordingto the invention over the person's upper dental arch; and

FIG. 6B illustrates dental bleaching trays according to the invention inplace over both the upper and lower dental arches.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS I. Introduction

The present invention relates to dental bleaching trays and strips usedto deliver a dental bleaching composition to a person's teeth. The traysand strips are formed from a moisture resistant material and include ableaching agent destabilizer compounded within the moisture resistantmaterial from which the barrier layer body is formed and/or disposed onan inner treatment surface of the barrier layer that is oriented towardand adjacent to the person's teeth during use.

II. Exemplary Chemically Activated Dental Bleaching Trays and Strips

FIG. 1 illustrates an exemplary non-custom dental bleaching tray 100which is formed from a moisture resistant material (e.g., a two-partsilicone). Dental bleaching tray 100 includes a barrier layer body 102in the shape of a tray. The tray shaped body 102 includes abuccal-labial front side wall 104, a lingual rear side wall 106, and abottom wall 108 bridging the buccal-labial wall 104 and buccal-labialwall 106. Bottom wall 108 is adjacent to buccal-labial wall 104 suchthat buccal-labial wall 104 extends laterally from bottom wall 108 in asubstantially vertical direction. Buccal-labial wall 104 is shown asincluding an optional v-shaped cut 105 formed along the top surfacethereof, near the center where the incisors reside during use. Such acut helps wall 104 to stretch and flex so as to better accommodate theincisors. Although not shown, such a similar cut or discontinuity may beformed within lingual wall 106. Lingual wall 106 is disposed at theopposite side of bottom wall 108, extending laterally upwardly andoutwardly therefrom. The buccal-labial wall 104, lingual wall 106, andbottom wall 108 together form a tray shaped body 102 having anapproximate U-shaped cross section and a generally horseshoe-shapedcurvature.

The size, shape and curvature of the tray body 102 are advantageouslyselected in order for the horseshoe-shaped curvature to generallyapproximate the curvature of a person's dental arch. The U-shaped crosssection generally corresponds to and defines an interior cavity of thetray body 102. The depth of the interior cavity is selected in order forthe buccal-labial and lingual walls 104 and 106 respectively to extendover a desired portion of a person's teeth, and optionally, over aportion of the person's gums.

Because of its non-custom nature (i.e., tray shaped body 102 issubstantially devoid of structures corresponding to the size and shapeof a person's unique dentition), the tray shaped barrier layer body 102comfortably fits over a plurality of differently sized and/or shapedteeth corresponding to different people. Nevertheless, it is within thescope of the invention to provide separate dental trays that are sizedand configured to correspond to either a person's upper or lower dentalarch, as the lower dental arch is typically smaller than the upper arch,with lower teeth that are typically smaller than the upper teeth. It isalso within the scope of the invention to provide varyingly-sizedbleaching trays to account for variability among different people'sdental arches and/or teeth (e.g., adults versus children, larger mouthsversus average or smaller mouths, and larger teeth versus average orsmaller teeth).

The tray body 102 may be injection molded, vacuum formed, cut and/orstamped from a sheet of polymeric material, although injection moldingis preferred over methods that involve cutting and/or stamping becausethe outer edges 109 of each wall may be injection molded so as to have asmooth, rounded edge surface as opposed to the sharp, angled surfacesformed when a tray is cut or stamped from a sheet of material. Suchsmooth edges also contribute to the overall comfortable feel of thetray.

Tray 100 includes an inner treatment surface 103 that includes theinwardly oriented surfaces of buccal-labial front side wall 104, bottomwall 108, and lingual rear side wall 106 that will be positioned againsttooth tissue to be bleached during use. At least a portion of innersurface 103 includes one or more bleaching agent destabilizers. In oneembodiment, the destabilizer may be compounded with the moistureresistant (e.g., polymeric) material from which the tray 100 is formed.In such an example, the destabilizer is distributed substantially evenlythroughout the material from which tray 100 is formed, so that at leastsome destabilizer is present on inner treatment surface 103. In anotherembodiment, the destabilizer may be applied to at least a portion ofinner surface 103, for example, by spraying, brushing, or otherwiseapplying the destabilizer onto the inner treatment surface 103.Advantageously, the destabilizer may be present on at least that portionof inner surface 103 corresponding to surfaces of the teeth to bebleached. For example, the destabilizer may be present on at least thelower portion of buccal-labial front side wall 104 nearest bottom wall108, which corresponds to the labial surface of the teeth to bebleached. Destabilizers may advantageously be absent from any portionsof the tray designed to contact gingival tissue, where no bleaching isto take place.

The one or more bleaching agent destabilizers act to destabilize theperoxide dental bleaching agent during use. When peroxides aredestabilized they more rapidly release free radicals, which cause toothbleaching. For example, it is believed that peroxide dental bleachingagents are destabilized to form predominantly hydroxyl (HO.) freeradicals, although peroxyl (.OOH), super oxide (.O), and super dioxide(.OO) free radicals may also be formed. Upon decomposition, which isaccelerated by the bleaching agent destabilizer, these free radicals aremore easily able to pass into the tooth enamel to the location of toothstains as compared to the larger peroxide (H₂O₂) molecules, which mayhave increased difficulty passing through tight spaces of the enamel tostain locations because of their larger size. The bleaching agentdestabilizer is advantageously retained on at least inner treatmentsurface 103 of the tray or strip prior to use, and upon contact with aperoxide dental bleaching agent in the presence of water; thedestabilizer becomes activated, resulting in formation of free radicalsfrom the peroxide for increased bleaching effect.

One class of bleaching agent destabilizers includes transition and/oralkaline earth metal ions. Non-limiting examples of suitable metal ionsinclude magnesium ions, iron ions, titanium ions, cobalt ions, nickelions, copper ions, platinum ions, tin ions, zinc ions, manganese ions,chromium ions, silver ions, aluminum ions, and combinations thereof.Magnesium and/or iron ions are particularly preferred. Another class ofbleaching agent destabilizer includes enzymes, particularlyorgano-metallic enzymes containing transition metals, such as iron.Examples include “peroxidase” and “catalase”, which is described moreparticularly in U.S. Pat. No. 6,485,709 to Banedjee et al., hereinincorporated by reference with respect to its disclosure oforgano-metallic enzymes.

One or more bleaching agent destabilizers including the above metal ionsin available form and/or organo-metallic enzymes are preferablycollectively included in an amount in a range of about 0.01% to about20% by weight of the polymeric material, more preferably in a range ofabout 0.05% to about 10% by weight, and most preferably about 0.1% toabout 5% by weight. Examples of suitable metal compounds includeiodides, nitrates, chlorates, borates, perchlorates, and perborates ofsuitable metal cations. Preferred specific compounds include MgO, ferricsulfate, ferric chloride, MnO₂, and TiO₂. Less preferred bleaching agentdestabilizers include elemental metals (e.g., iron, silver, platinum,copper, magnesium, titanium, cobalt, nickel, tin, zinc, chromium,aluminum, and/or manganese in powder form). Of course, any other metalions mentioned herein may also be used in elemental form. Another classof bleaching agent destabilizers that may be used include iodine salts(e.g., potassium iodide and/or sodium iodide).

Many of the metal ion containing compounds are believed to react withthe peroxide bleaching agent according to Fenton's Reaction, forexample, ferric Fe²⁺ ions react to form ferrous Fe³⁺ ions in thepresence of peroxide, releasing oxygen free radicals. During the courseof the reaction, the peroxide is regenerated, allowing more ferric ionsto react, resulting in production of more oxygen free radicals.

FIG. 2A illustrates an alternative non-custom dental bleaching tray 200that includes anatomical structural features that allow tray 200 to moreclosely conform to a person's teeth during use. Body 202 includes abuccal-labial front side wall 204, a bottom wall 208, and a lingual sidewall 206 connected to bottom wall 208 at an opposite side relative tobuccal-labial wall 204. An inner treatment surface 203 is defined byinterior portions of bottom wall 208, buccal-labial front side wall 204,and lingual side wall 206. Illustrated tray 200 is sized and configuredfor placement over a person's upper dental arch. As illustrated, lingualwall 206 may advantageously include a notch 205, which allows thenon-custom tray 200 to more easily spread open or compress in the areaof the incisors. This is helpful in allowing the lingual wall 206 of thenon-custom tray 200 to more easily conform to differently-sized dentalarches. Bottom wall 204 includes an abrupt reduction in width positionedat locations 210 corresponding to a transition between posterior teeth(i.e., bicuspids and molars) and anterior teeth (i.e., canines andincisors). Bottom wall 208 also advantageously includes two v-shapedindentations 216 for insertion into the depression between the occlusalpeaks of the posterior teeth (i.e., the bicuspids and molars).

Similar to tray 100, at least a portion of inner surface 203 of tray 200includes one or more bleaching agent destabilizers. In a preferredexample, the one or more dental bleaching agent destabilizers may becompounded with the moisture resistant polymeric material from which thetray 200 is formed. In such an example, the destabilizers may bedistributed substantially evenly throughout the material from which tray200 is formed, so that at least some destabilizer is present on innertreatment surface 203. Alternatively, one or more bleaching agentdestabilizers may be applied (e.g., after molding or otherwise formingtray body 202) to at least a portion of inner treatment surface 203where dental bleaching composition will be applied during use, and whichsurfaces of the tray will be placed against tooth tissues to be bleachedduring use.

FIG. 2A is an exploded view showing the dental bleaching tray 200 incombination with a corresponding optional outer support tray 250 that iscomplementarily shaped so as to be capable of receiving the dentalbleaching tray 200 in a nested configuration (see FIG. 2B). The outersupport tray 250 may include the same anatomical features as tray 200 inorder to provide a closer fit. The outer support tray 250 advantageouslyincludes a handle 252 extending outwardly from a central portion of thebuccal-labial front wall in order to facilitate gripping by the userduring placement of the dental bleaching tray 200 over the person'steeth.

In FIG. 2B, dental bleaching tray 200 is nested within outer supporttray 250 so as to form a dental tray assembly 255. The handle 252extends beyond the buccal-labial wall of tray 200 in order to facilitateplacement and removal of the outer support tray 250 after placement oftray 200 over the person's teeth.

FIG. 3 illustrates an exemplary dental bleaching strip 400 which isformed from a polymeric material. Dental bleaching strip 400 isinitially substantially rectangular and includes a planar surface 402which can be positioned adjacent the teeth to be bleached and foldedalong the incisal edge of the teeth so as to cover the labial andincisal tooth surfaces. Depending on the position of the fold duringplacement, a portion (or substantially all) of the lingual toothsurfaces may also be covered by the strip 400 once placed. At least aportion of planar surface 402 defines an inner treatment surfacecorresponding to portions of surface 402 which are positioned adjacentto particularly the labial teeth surfaces during use.

At least a portion of inner planar surface 402 oriented toward aperson's tooth surfaces includes one or more bleaching agentdestabilizers. In a preferred example, the one or more dental bleachingagent destabilizers may be compounded with the moisture resistantpolymeric material from which the strip 400 is formed. In such anexample, the destabilizers may be distributed substantially evenlythroughout the material from which strip 400 is formed, so that at leastsome destabilizer is present on planar treatment surface 402.Alternatively, one or more bleaching agent destabilizers may be applied(e.g., after forming of strip barrier layer 400) to at least a portionof inner treatment planar surface 402 where dental bleaching compositionwill be applied during use and which surfaces of the strip will beplaced against tooth tissues to be bleached during use.

Although conventional strips are less effective in bleaching teethrelative to tray shaped barrier layers because strips tend to readilyslip off and/or become mangled before treatment is complete, an improveddental bleaching strip can be provided according to the presentinvention by providing a bleaching agent destabilizer compounded withinor otherwise disposed on an inner treatment surface of the strip. Suchstrips may provide for improved bleaching as the destabilizer acts topromote formation of active bleaching free radicals from the peroxidebleaching agent, which may be expected to result in faster bleaching, atleast partially counteracting the disadvantages (i.e., tendency to slipoff and/or mangle) of strips.

Any dental tray or strip according to the invention may be providedseparately from a dental bleaching composition, which is introduced intothe tray (e.g., adjacent the tray's inner treatment surface) or appliedonto the strip by the user immediately prior to use so that there is nocontact between the bleaching agent destabilizer of the barrier layerand the bleaching composition until treatment begins. In one alternativeembodiment, it may be possible to prefill a tray or preapply a dentalbleaching composition to a strip if the bleaching composition isanhydrous. The anhydrous dental bleaching composition may be disposeddirectly in contact with the barrier layer, and will not reactprematurely because of the anhydrous nature of the bleachingcomposition. As soon as water is added to the system (e.g., whencontacted by saliva by placing the pre-filled tray or pre-applied stripon the teeth), reaction between the destabilizer and bleaching agentwill begin. Embodiments including an anhydrous dental bleachingcomposition may advantageously be sealed within a protective package toprevent absorption of water from the surrounding air during shipment andstorage.

Another alternative embodiment may include an anhydrous adhesivecomposition (e.g., including polyvinyl pyrollidone as an adhesive agent)that also includes a bleaching agent destabilizer (e.g., potassiumiodide). The adhesive destabilizing composition may be coated over thebarrier layer (e.g., as a thin layer or film). It is important to notethat such a composition including the bleaching agent destabilizer isapplied to a region of the barrier layer corresponding to the toothsurfaces to be bleached. In other words, if the composition is notapplied over substantially the entire interior surface of the barrierlayer tray or strip, it is at least applied to that portion of thebarrier layer which in use is positioned against the tooth surfaces tobe bleached (e.g., at least the labial tooth surface). It is notnecessary to apply the bleaching agent destabilizer to regions of thebarrier layer which will be positioned against gum tissue during use. Infact it may be preferable in some embodiments to ensure that nobleaching agent destabilizer is present in regions of the barrier layerwhich will be positioned against gingival tissue so as to preventreaction with peroxide bleaching agents adjacent the gingival tissue,which may otherwise cause discomfort and soreness. Of course, inembodiments where the destabilizer is compounded within the material ofthe barrier layer this may be impractical, although discomfort togingival tissues may be prevented by limiting application of thebleaching composition to regions of the barrier layer corresponding totooth surfaces to be bleached.

In other words, it may be preferred to apply the bleaching compositionso that substantially no bleaching composition is applied adjacent anypart of the barrier layer that will be positioned adjacent the gingivaltissue, so that the bleaching agent and the destabilizer are onlypresent together at portions of the tray corresponding to tooth surfacesto be bleached. In embodiments where the destabilizer is applied as afilm or composition layer, it may be preferable to maintain any portionsof the barrier layer which will be positioned adjacent to gingivaltissue so that they are substantially free of the bleaching agentdestabilizers, and that the destabilizer film or layer is only appliedto those portions of the barrier layer corresponding to tooth surfacesto be bleached (e.g., at least the labial tooth surface). In otherwords, in any embodiment, the bleaching agent and the destabilizer maybe present together only at those portions of the tray corresponding totooth surfaces to be bleached. At portions of the tray that will bepositioned adjacent to gingival tissue during use, only one or the other(or neither) of the bleaching agent destabilizer and the bleaching agentare present so as to prevent discomfort and soreness.

In embodiments where the adhesive destabilizer composition is anhydrous,a peroxide bleaching agent may also be included, so long as no water ispresent so as to prevent premature reaction between the bleaching agentdestabilizer and the peroxide bleaching agent. Alternatively, ableaching composition (e.g., an aqueous gel) may be applied over thelayer or film adhesive layer just prior to use. The water within thebleaching composition and/or saliva within the user's mouth causes thebleaching agent destabilizer to be activated in the presence of thebleaching agent.

In another alternative embodiment, a non-custom dental tray or stripaccording to the invention may be preloaded with a dental bleachingcomposition. In order to prevent premature contact between the bleachingagent destabilizer and bleaching composition, the tray or strip furtherincludes a protective rupturable membrane disposed between the barrierlayer and the bleaching composition. The membrane may be configured tobe rupturable subsequent to placement of the tray over the person'steeth. For example, a rupturable membrane of a tray or strip bleachingdevice may be configured to rupture upon biting, bending and/or foldingof the barrier layer and membrane. Such a rupturable membrane maycomprise any rupturable layer that is disposed between the bleachingcomposition and the tray or strip including a bleaching agentdestabilizer. Examples of suitable materials include a protectivecoating layer of high molecular weight polyethylene glycol, adi-para-xylene coating layer, and/or a wax coating. Di-para-xylene isavailable commercially as Parylene from Parylene Coating Services, Inc.,located in Katy, Tex. Such coatings may serve to simply separate thebleaching composition from the barrier layer during storage andshipment, and the coating membrane is ruptured upon biting, bending,and/or flexing of the tray or strip. The rupturable membrane layer maybe water-degradable so as to dissolve, degrade, or become dispersed uponcontact with moisture (e.g., saliva).

Such a tray or strip may be provided within a sealed container orpackage to protect the tray or strip, the bleaching composition, andrupturable membrane from contaminants and/or premature rupture duringstorage, transport, and prior to use. FIG. 4 shows a first tray assembly355 configured for placement over an upper dental arch and a second trayassembly 355′ configured for placement over a lower dental arch sealedwithin protective package 356. Each tray 300 and 300′ includes ableaching composition 354 pre-loaded therein. Protective package 356includes a rigid support layer 358 and a peelable cover 360. Each trayassembly 355 and 355′ may optionally include an additional removableprotective layer (not shown) placed adjacent to the bleachingcomposition 354 for additional protection. When it is desired to use thedental bleaching tray devices, the peelable cover 360 is removed and thetray assemblies 355 and 355′ are removed or separated from support layer358.

FIG. 5 illustrates a cross-sectional view through tray assembly 355 ofFIG. 4, including tray 300 and outer support tray 350, perhaps bestillustrating protective rupturable membrane 357 disposed adjacent toinner treatment surface 303 of tray 300.

Another embodiment may include a multi-use tray, for example a customdental tray formed by vacuum forming a sheet of moisture resistantthermoplastic polymer material over a stone cast of a person's teeth,after which the custom tray may be cut out. Such custom trays can bevery comfortable to wear as they provide an excellent fit to the user'sdentition. A bleaching agent destabilizer (e.g., a ferric salt) may becompounded with the tray material or otherwise provided so that thebleaching agent destabilizer is present on the interior treatmentsurface of the tray. During use, the user applies a bleachingcomposition into the tray, and then places the tray over the teeth forbleaching treatment. The bleaching agent destabilizer, for example, aferric salt, is oxidized during use so as to form ferrous ions. Becauseat least some of the bleaching agent destabilizer will likely remainafter use, the custom tray may be used multiple times before all thebleaching agent destabilizer has been consumed. Once all bleaching agentdestabilizer has been consumed, the custom tray may still be used as aconventional custom bleaching tray, although it will no longer providethe increased bleaching effect afforded by the bleaching agentdestabilizer.

The trays and strips may be used with any known dental bleachingcomposition. Exemplary bleaching compositions include a peroxide dentalbleaching agent. The bleaching composition may comprise a sticky viscousgel, a less viscous gel, a highly viscous putty, or a substantiallysolid composition that is less adhesive prior to being moistened withsaliva or water but that becomes more sticky and adhesive whenmoistened.

According to one embodiment, the barrier layer comprises a thin (e.g.,about 1 mm or less), flexible membrane formed from a polymeric or othermoisture-resistant material. Polymeric materials are preferred. In oneembodiment, the barrier layer comprises silicone. In another, itcomprises ethyl vinyl acetate and polypropylene. According to anotherembodiment, it may be formed of a polyolefin or similarlymoisture-resistant material, such as wax, paraffin, ethylene-vinylacetate copolymer (EVA), ethylene-vinyl alcohol copolymer (EVAL),polycaprolactone (PCL), polyvinyl chloride (PVC), polyesters,polycarbonates, polyamides, polyurethanes or polyesteramides. Examplesof suitable polyolefins for use in making the barrier layer include, butare not limited to, polyethylene (PE), high density polyethylene (HDPE),low density polyethylene (LDPE), ultra low density polyethylene (ULDPE),polypropylene, and polytetrafluoroethylene (PTFE) (e.g., TEFLON). Anexample of a suitable polyester for use in making the barrier layerincludes, but is not limited to, polyethylene terephthalate (PET), anexample of which is MYLAR, sold by DuPont. An example of a suitablepolyurethane barrier material is a polyurethane film manufactured byArgoTech, which is located in Greenfield, Mass. The barrier layer maycomprise a polymeric blend and/or multiple layers comprising two or moreof the foregoing materials. Plasticizers, flow additives, and fillersknown in the art can be used as desired to modify the properties of anyof the foregoing polymers used to form the barrier layer. The forgoinglisting of polymeric materials is not meant to be exhaustive, asnumerous other polymeric materials may be used.

Other materials that can act as a barrier layer include metal foil,cellulosic ethers, cellulose acetate, polyvinyl acetate, polyvinylalcohol, shellac, and chemical or light-cure materials (e.g.,methacrylate or acrylate resins). Examples of useful cellulosic ethersthat can be used to form a barrier layer include, but are not limitedto, ethyl cellulose, propyl cellulose, isopropyl cellulose, butylcellulose, t-butyl cellulose, and the like. Although non-polymericmoisture resistant materials, e.g., metal foil, may be used, polymericmaterials are preferred.

Silicone and silicone like materials (i.e., materials exhibiting similarphysical characteristics) are one preferred class of polymeric materialsfor forming the barrier layer because of their excellent adaptability,flexibility, softness, elasticity, and resiliency. Exemplary suitabletwo-part silicone materials are available from Shin-Etsu Silicones ofAmerica, located in Akron, Ohio. One preferred material isKEG2000-50A/B, the physical properties of which are described in thetable below. Various other Shin-Etsu silicone products and siliconematerials from other suppliers can also be used.

Property Value Hardness - Shore-A 52 Tensile Strength - MPa 11.1Elongation - % 580 100% Modulus - Mpa 1.72 Tear Strength - kN/m 40 CompSet 22 h/302° F.-1 h/302° F. 31 Comp Set 22 h/302° F.-4 h/392° F. 8Linear Shrinkage 2.6 Specific Gravity 1.13 Viscosity - Part A-Pa · s1700 Viscosity - Part B-Pa · s 1600

For example, a silicone material may initially comprise a two-partcomposition including a first part comprising one or more siloxanes anda second part including an activator. Upon mixing the two liquid partstogether, the siloxane molecules polymerize and cross-link so as to forma polysiloxane. Heat may be applied (e.g., by heating the mold) toaccelerate polymerization of the silicone material. For example, part Aand part B of the raw silicone precursor material are mixed together,which causes the material to begin to polymerize. For many exemplarysilicone materials, this reaction could take 2-6 weeks to completelycure at room temperature. Heating the mixture significantly increasesthe rate at which the material polymerizes. For example, according toone method, the material is heated to 375° F. so as to cause thematerial to polymerize in a matter of seconds. Actual polymerizationtime depends on the thickness of the tray or strip being formed.Silicone trays and/or strips may also be formed by other methods, forexample with a two part silicone in which polymerization is activated bymixing and/or by compression.

Silicone polymeric materials include a platinum and/or tin catalystwithin one or both parts of the composition to assist withpolymerization. Advantageously, residual catalyst is present within thematerial after the tray or strip has been formed. Residual platinumand/or tin catalyst disposed throughout the material, including on theinner treatment surface of the tray or strip, can also act as ableaching agent destabilizer, acting to produce free radicals from theperoxide bleaching agent upon contact of the barrier layer with aperoxide bleaching composition. Although platinum is a less preferreddestabilizer because of its generally higher cost, it is within thescope of the present invention to utilize platinum when present. As theplatinum and/or tin may be included in small, silicone-catalyzingamounts (e.g., typically less than 1000 ppm, more typically less than100 ppm), it may be advantageous to include an additional, morepreferred destabilizer, for example magnesium and/or iron in addition tothe residual platinum and/or tin, in order to boost the overalldestabilizing effect.

Styrene-ethylene-butylene-styrene (SEBS), and/or VERSAflex, aproprietary thermoplastic elastomer alloy exhibiting elasticity andother properties similar to silicone, are examples of silicone-likematerials. A suitable example of a SEBS material is SEBS TPE 45A,available from various providers. Physical properties for SEBS TPE 45Aare summarized in the table below. Various other SEBS products may alsobe used in forming a polymeric moisture resistant barrier layer.

Property Value Density (g/cm³) 0.94 Surface Hardness-Shore A 45 TensileStrength (MPa) 6 Flexural Modulus (GPa) 0.02 Notched Izod (kJ/m) 1.06+Linear Expansion (/° C. × 10⁻⁵) 16 Elongation at Break (%) 800 WaterAbsorption (%) 0.3 Oxygen Index (%) 19 Melting Temp. Range (° C.)200-240 Mold Shrinkage (%) 1.5 Mold Temp. Range (° C.) 50-70

Several suitable VERSAFLEX TPE materials are available from GLSCorporation, located in McHenry, Ill. Preferred VERSAFLEX materialsinclude VERSAFLEX CL30 and VERSAFLEX CL40, properties of each of whichare summarized in the table below. Various other VERSAFLEX products fromGLS Corporation can also be used.

Product Property CL30 CL40 Test Method Shore A Hardness, 10 sec delay 3043 ASTM D2240 Specific Gravity 0.89 0.89 ASTM D792, 23/23° C. TensileStrength 6619 kPa 5929 kPa ASTM D412-Die C, 2 hrs, 23° C. Elongation atBreak 780% 690% ASTM D412-Die C, 2 hrs, 23° C. 100% Modulus 689 kPa 1379kPa ASTM D412-Die C, 2 hrs, 23° C. 300% Modulus 1448 kPa 2413 kPa ASTMD412-Die C, 2 hrs, 23° C. Tear Strength 19 kN/m 23 kN/m ASTM D624 MeltFlow Rate @ 190° C., 2160 g 18 g/10 min 13 g/10 min ASTM D 1238 MeltFlow Rate @ 200° C., 5000 g 108 g/10 min 38 g/10 min ASTM D 1238Apparent Viscosity @ 200° C. 11170/sec 15 Pa-s 16 Pa-s ASTM D 3835Compression Set, 22 hrs @ RT 11% 12% ASTM D 395B

Preferred dental bleaching trays are characterized by wall thicknessesof no more than about 1 mm, more preferably between about 0.03 mm andabout 1 mm, and most preferably between about 0.1 mm and about 0.5 mm.Wall thicknesses greater than about 1 mm are significantly less usefulas a comfortable dental bleaching tray, as the thickness of the traybegins to seriously interfere with the normal relaxed position of theocclusal tooth surfaces when wearing such a tray (i.e., the tray(s) getin the way between teeth of opposite dental arches, preventing the userfrom completely closing their jaw), making the tray significantly lesscomfortable than a tray with wall thicknesses that are no more thanabout 1 mm. For this same reason, existing mouth guards formed ofsilicone have little or no use as a comfortable dental treatment tray astheir wall thickness is typically greater than 2 mm, and more typicallyabout 4 mm so as to provide a cushioning effect to the teeth whenaccepting a blow to the mouth or jaw. Similarly, the inventive dentalbleaching trays would be unacceptable for use as a mouth guard, as theirthin walls provide little or no protection to the teeth against suchblows.

The dental bleaching trays according to the invention can be designed tobe worn for any desired time period. Due to the extremely comfortablefit between the inventive dental bleaching trays and the person's teeth,it is possible to wear such trays for extended periods of time asdesired. The dental bleaching trays can be worn for as little as a fewminutes or as long as several hours. By way of example, not limitation,a typical bleaching session of fast duration may last from about 10 toabout 30 minutes; a bleaching session of intermediate duration may lastfrom about 30 minutes to about 2 hours; and a bleaching session of longduration, including overnight bleaching while a person is sleeping, maylast from about 2 hours to about 12 hours.

When used in combination with a sticky bleaching composition, dentalbleaching trays may possibly be worn while performing normal dailyactivities, such as talking, drinking, smoking, coughing, smiling,frowning, grimacing, or while sleeping. Dental bleaching trays accordingto the invention may be worn over a person's upper dental arch, lowerdental arch, or both simultaneously. Although trays provide an improvedfit as compared to strips, it is of course within the scope of theinvention to provide dental bleaching strips which can also be used toprovide similar treatment. Such strips may be expected to be worn forsimilar ranges of time as described above, and when used with aninitially dry bleaching composition that becomes very sticky uponcontact with water, may even be worn while engaging in the abovedescribed activities as the bleaching composition (e.g., a substantiallydry bleaching composition) more effectively holds the strip in placeagainst the tooth tissues to be bleached.

FIG. 6A illustrates a person 375 placing a dental bleaching assembly 355over the person's upper dental arch. The outer support tray helps inplacing the inner bleaching tray over the teeth. FIG. 6B illustrates adental bleaching tray 300 in place over the person's upper dental archand a dental bleaching tray 300′ over the lower dental arch, both outersupport trays having been removed.

To remove the dental bleaching tray after a desired time period, theuser simply grasps a corner or portion of the tray and pulls it off theteeth. Any residual bleaching composition that remains adhered to theperson's teeth can be removed by washing or flushing with water and/orby brushing.

EXAMPLES OF THE PREFERRED EMBODIMENTS

Following are examples of polymeric compositions that may be used tomanufacture dental bleaching trays according to the invention. Theexemplary formulations and manufacturing conditions are given by way ofexample, and not by limitation. Unless otherwise indicated, allpercentages are by weight.

Example 1

A composition for injection molding a silicone dental treatment tray wasformed from Shin-Etsu's KEG2000-50A/B two part thermoset siliconematerial. Part A containing the activator/hardener had a viscosity ofabout 1700 Pa-s, while part B containing the siloxane had a viscosity ofabout 1600 Pa-s. At least one part included a platinum catalyst.

The two parts of the silicone composition were pumped out of storagedrums through hoses to a static mixing head where the two parts weremixed together. The mixed silicone material exits the static mixer andwas forced into the screw and barrel of the injection molding machine.The mixed silicone material was injected into the heated mold (e.g.,about 375° F.), at which point the material quickly polymerized. Thetray was removed from the hot mold after polymerization wassubstantially complete. Exemplary formed trays exhibited excellentadaptability, flexibility, elasticity, and softness, while also beingresilient. The molded trays were translucent, had a Shore A durometerhardness of about 50, an elasticity of about 580%. Trays having wallthicknesses of about 0.004 inch (0.10 mm), 0.006 inch (0.15 mm), 0.008inch (0.2 mm), 0.01 inch (0.25 mm) and 0.014 inch (0.36 mm),respectively, were formed. It is believed that the residual platinumcatalyst content within the finished tray was less than 1000 ppm, morelikely less than 100 ppm. The presence of residual platinum catalystwithin the silicone material provided available platinum ions to act asa bleaching agent destabilizer when contacted with a peroxide dentalbleaching agent.

Example 2

A composition for injection molding a dental treatment tray was formedfrom SEBS TPE 45A material. The heated material was pumped so as to beforced into the screw and barrel of the injection molding machine. Thematerial was injected into the mold. The cooled tray was removed fromthe mold. Exemplary formed SEBS trays exhibited excellent adaptability,flexibility, elasticity, and softness, while also being resilient,similar to the silicone tray of Example 1. The molded trays weretranslucent, had a Shore A durometer hardness of about 45, an elasticityof about 800% and a wall thickness of about 0.020 inch (0.5 mm). Thetrays were found to be very comfortable when worn over a person's dentalarch, with excellent adaptability, flexibility, elasticity, softness,and resiliency. A bleaching agent destabilizer (e.g., about 0.1 percentto about 5 percent by weight) may be compounded with the SEBS materialprior to molding so that the finished trays include the bleaching agentdestabilizer on the inner surface of the tray.

Example 3

A composition for injection molding a dental treatment tray is formedfrom VERSAFLEX CL30. The heated TPE material is pumped so as to beforced into the screw and barrel of the injection molding machine. Thematerial is injected into the mold. The cooled tray is removed from themold. Exemplary formed VERSAFLEX CL30 trays exhibit excellentadaptability, flexibility, elasticity, and softness, while also beingresilient, similar to the silicone tray of Example 1. The molded traysare translucent, have a Shore A durometer hardness of about 30, anelasticity of about 780% and a wall thickness of about 0.020 inch (0.5mm). The trays are very comfortable when worn over a person's dentalarch, with excellent adaptability, flexibility, elasticity, softness,and resiliency A bleaching agent destabilizer (e.g., about 0.1 percentto about 5 percent by weight) may be compounded with the VERSAFLEXmaterial prior to molding so that the finished trays include thebleaching agent destabilizer on the inner surface of the tray.

Example 4

A composition for injection molding a dental treatment tray is formedfrom VERSAFLEX CL40. The heated TPE material is pumped so as to beforced into the screw and barrel of the injection molding machine. Thematerial is injected into the mold. The cooled tray is removed from themold. Exemplary formed VERSAFLEX CL40 trays exhibit excellentadaptability, flexibility, elasticity, and softness, while also beingresilient, similar to the silicone tray of Example 1. The molded traysare translucent, have a Shore A durometer hardness of about 40, anelasticity of about 690% and a wall thickness of about 0.020 inch (0.5mm). The trays are very comfortable when worn over a person's dentalarch, with excellent adaptability, flexibility, elasticity, softness,and resiliency A bleaching agent destabilizer (e.g., about 0.1 percentto about 5 percent by weight) may be compounded with the VERSAFLEXmaterial prior to molding so that the finished trays include thebleaching agent destabilizer on the inner surface of the tray.

Example 5

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 450 98% Ferric sulfate  2%

All fractions are by weight. ELVAX 450 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the ferric sulfate bleaching agentdestabilizer on the inner surface of the tray.

Example 6

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 450 98% Ferric chloride  2%

All fractions are by weight. ELVAX 450 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the ferric chloride bleaching agentdestabilizer on the inner surface of the tray.

Example 7

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 450 98% Magnesium powder  2%

All fractions are by weight. ELVAX 450 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the elemental magnesium bleaching agentdestabilizer on the inner surface of the tray.

Example 8

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 450 98% Iron powder  2%

All fractions are by weight. ELVAX 450 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the elemental iron bleaching agentdestabilizer on the inner surface of the tray.

Example 9

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 450 98% Copper powder  2%

All fractions are by weight. ELVAX 450 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the elemental copper bleaching agentdestabilizer on the inner surface of the tray.

Example 10

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 450 98% Nickel powder  2%

All fractions are by weight. ELVAX 450 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the elemental nickel bleaching agentdestabilizer on the inner surface of the tray.

Example 11

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 450 98% Aluminum powder  2%

All fractions are by weight. ELVAX 450 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the elemental aluminum bleaching agentdestabilizer on the inner surface of the tray.

Example 12

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 450 98% Chromium powder  2%

All fractions are by weight. ELVAX 450 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the elemental chromium bleaching agentdestabilizer on the inner surface of the tray.

Example 13

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 450 98% Zinc powder  2%

All fractions are by weight. ELVAX 450 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the elemental zinc bleaching agentdestabilizer on the inner surface of the tray.

Example 14

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 450 98% Titanium powder  2%

All fractions are by weight. ELVAX 450 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the elemental titanium bleaching agentdestabilizer on the inner surface of the tray.

Example 15

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 250 98% Magnesium powder  2%

All fractions are by weight. ELVAX 250 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the elemental magnesium bleaching agentdestabilizer on the inner surface of the tray.

Example 16

A composition for injection molding a dental treatment tray was formedby combining and mixing the following materials:

ELVAX 720 98% Magnesium powder  2%

All fractions are by weight. ELVAX 720 is an EVA polymeric materialavailable from Dupont. The heated material was pumped so as to be forcedinto the screw and barrel of the injection molding machine. The materialwas injected into the mold. The cooled tray was removed from the mold.The finished trays included the elemental magnesium bleaching agentdestabilizer on the inner surface of the tray.

Following is an example of a dental bleaching composition that can beused in combination with dental bleaching trays or strips including ableaching agent destabilizer. The dental bleaching composition may bepre-loaded in a tray or pre-applied to a strip.

Example 17

A sticky, viscous dental bleaching composition was prepared by mixingtogether the following components:

Water 22.5% EDTA Disodium  0.1% Carbamide Peroxide 18.5% Sucralose 25%solution 0.75% Glycerine 41.6% Carbopol 974  5.3% Sodium Hydroxide 50%solution 2.25% Polyvinyl Pyrrolidone (M.W. = 1.3 million)   2%Carboxymethyl Cellulose   4% Watermelon Flavor   3%

All fractions are by weight. A bite ruptureable membrane is positionedadjacent the inner treatment surface of a tray shaped or strip shapedbarrier layer. A bead of dental bleaching composition is then spreadalong the ruptureable barrier layer adjacent the dental bleaching tray.The bleaching composition may be positioned adjacent the labial-buccalwall of the tray, as illustrated in FIG. 5. In the case of a strip, thedental bleaching composition is applied evenly over one side of thestrip shaped barrier layer, with the rupturable membrane between thecomposition and the barrier layer. During placement and/or use therupturable membrane is broken, contacting the composition to the barrierlayer. Upon contact of the bleaching composition with the barrier layer,the peroxide dental bleaching agent is destabilized so as to accelerateproduction of free radicals. The trays and strips reliably adhere totooth tissue, and exhibit excellent comfort and adhesiveness.

Additional exemplary dental bleaching compositions, and methods formaking such compositions, which may be used with devices according tothe invention are disclosed in U.S. Pat. No. 5,376,006; U.S. Pat. No.5,785,527; U.S. Pat. No. 5,851,512; U.S. Pat. No. 5,858,332; U.S. Pat.No. 5,985,249; U.S. Pat. No. 6,306,370; U.S. Pat. No. 6,309,625; U.S.Pat. No. 6,312,671; U.S. Pat. No. 6,322,774; U.S. Pat. No. 6,368,576;U.S. Pat. No. 6,387,353; U.S. Pat. No. 6,500,408; U.S. Pat. No.6,503,485 and U.S. patent application Ser. No. 11/460,016 filed Jul. 26,2006. For purposes of disclosing dental bleaching compositions, andmethods of making such compositions, the foregoing patents andapplication are incorporated herein by reference.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A thin-walled, non-custom disposable dental bleaching tray or stripfor use in applying a dental bleaching composition to a person's teeth,comprising: a barrier layer formed from a moisture resistant material,the barrier layer having a wall thickness less than about 1 mm and beingin the shape of a tray or a strip, the barrier layer having an innertreatment surface that is oriented toward a person's teeth during use;and a bleaching agent destabilizer compounded with and/or disposed onthe inner treatment surface of the barrier layer such that at least someof the bleaching agent destabilizer is disposed on the inner treatmentsurface of the barrier layer.
 2. A dental bleaching tray or strip asrecited in claim 1, wherein the bleaching agent destabilizer comprises atransition and/or alkaline earth metal source.
 3. A dental bleachingtray or strip as recited in claim 2, wherein the bleaching agentdestabilizer comprises a transition and/or alkaline earth metal sourceselected from the group consisting of titanium, cobalt, nickel, copper,platinum, tin, zinc, manganese, aluminum, silver, and chromium.
 4. Adental bleaching tray or strip as recited in claim 2, wherein thebleaching agent destabilizer comprises at least one of magnesium oriron.
 5. A dental bleaching tray or strip as recited in claim 1, whereinthe bleaching agent destabilizer comprises iodine.
 6. A dental bleachingtray or strip as recited in claim 1, wherein the bleaching agentdestabilizer comprises an organo-metallic enzyme.
 7. A dental bleachingtray or strip as recited in claim 6, wherein the organo-metallic enzymecomprises catalase and/or peroxidase.
 8. A dental bleaching tray orstrip as recited in claim 1, wherein the bleaching agent destabilizercomprises between about 0.1 percent and about 5 percent by weight of thebarrier layer.
 9. A dental bleaching tray as recited in claim 1, whereinthe barrier layer has a thickness between about 0.03 mm and about 1 mm.10. A dental bleaching tray as recited in claim 1, wherein the barrierlayer has a thickness between about 0.1 mm and about 0.5 mm.
 11. Adental bleaching tray or strip as recited in claim 1, wherein themoisture resistant material comprises a polymeric material and thebleaching agent destabilizer is compounded within the polymeric materialof the barrier layer such that the destabilizer is substantially evenlydistributed throughout the polymeric material of the barrier layer. 12.A dental bleaching tray or strip as recited in claim 1, furthercomprising an anhydrous dental bleaching composition comprising aperoxide bleaching agent, the anhydrous dental bleaching compositionbeing disposed adjacent to the inner treatment surface of the barrierlayer.
 13. A dental bleaching tray or strip comprising: a tray shaped orstrip shaped barrier layer formed from a moisture resistant material andhaving an inner treatment surface that is oriented toward a person'steeth during use; and a transition and/or alkaline metal bleaching agentdestabilizer selected from the group consisting of magnesium and iron,the bleaching agent destabilizer being compounded with the moistureresistant material such that at least some of the magnesium and/or ironis disposed on the inner treatment surface of the tray shaped or stripshaped barrier layer.
 14. A dental bleaching tray or strip as recited inclaim 13, wherein the metal ions comprise between about 0.1 percent andabout 5 percent by weight of the barrier layer.
 15. A pre-filled dentalbleaching tray or strip comprising: a tray shaped or strip shapedbarrier layer comprising a moisture resistant material and a bleachingagent destabilizer compounded with and/or on an inner treatment surfaceof the barrier layer such that at least some of the bleaching agentdestabilizer is disposed on the inner treatment surface of the barrierlayer; a dental bleaching composition comprising a peroxide bleachingagent; and a protective rupturable membrane disposed between the innertreatment surface of the barrier layer and the dental bleachingcomposition so as to prevent premature contact between the bleachingagent destabilizer and the peroxide bleaching agent.
 16. A dentalbleaching tray or strip as recited in claim 15, wherein the bleachingagent destabilizer comprises a transition and/or alkaline earth metalsource.
 17. A dental bleaching tray or strip as recited in claim 16,wherein the bleaching agent destabilizer comprises a transition and/oralkaline earth metal source selected from the group consisting oftitanium, cobalt, nickel, copper, platinum, tin, zinc, manganese,aluminum, silver, and chromium.
 18. A dental bleaching tray or strip asrecited in claim 16, wherein the bleaching agent destabilizer comprisesat least one of magnesium or iron.
 19. A dental bleaching tray or stripas recited in claim 15, wherein the bleaching agent destabilizercomprises an organo-metallic enzyme.
 20. A dental bleaching tray orstrip as recited in claim 19, wherein the organo-metallic enzymecomprises catalase and/or peroxidase.
 21. A dental bleaching tray orstrip as recited in claim 15, wherein the bleaching agent destabilizercomprises between about 0.1 percent and about 5 percent by weight of thebarrier layer.
 22. A dental bleaching tray or strip as recited in claim15, wherein the bite ruptureable membrane comprises at least one of ahigh molecular weight polyethylene glycol, parylene, or wax.